1 /*
2 * Copyright © 2019 Collabora Ltd
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 #include "nir.h"
25 #include "nir_builder.h"
26
27 /** nir_lower_point_size_mov.c
28 *
29 * This pass lowers glPointSize into gl_PointSize, by adding a uniform
30 * and a move from that uniform to VARYING_SLOT_PSIZ. This is useful for
31 * OpenGL ES level hardware that lack constant point-size hardware state.
32 */
33
34 static bool
lower_impl(nir_function_impl * impl,const gl_state_index16 * pointsize_state_tokens,nir_variable * out)35 lower_impl(nir_function_impl *impl,
36 const gl_state_index16 *pointsize_state_tokens,
37 nir_variable *out)
38 {
39 nir_shader *shader = impl->function->shader;
40 nir_builder b;
41 nir_variable *in, *new_out = NULL;
42
43 b = nir_builder_create(impl);
44
45 in = nir_state_variable_create(shader, glsl_vec4_type(),
46 "gl_PointSizeClampedMESA",
47 pointsize_state_tokens);
48
49 /* the existing output can't be removed in order to avoid breaking xfb.
50 * drivers must check var->data.explicit_location to find the original output
51 * and only emit that one for xfb
52 */
53 if (!out || out->data.explicit_location) {
54 new_out = nir_create_variable_with_location(shader, nir_var_shader_out,
55 VARYING_SLOT_PSIZ, glsl_float_type());
56 }
57
58 if (!out) {
59 b.cursor = nir_before_impl(impl);
60 nir_def *load = nir_load_var(&b, in);
61 load = nir_fclamp(&b, nir_channel(&b, load, 0), nir_channel(&b, load, 1), nir_channel(&b, load, 2));
62 nir_store_var(&b, new_out, load, 0x1);
63 } else {
64 bool found = false;
65 nir_foreach_block_safe(block, impl) {
66 nir_foreach_instr_safe(instr, block) {
67 if (instr->type == nir_instr_type_intrinsic) {
68 nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
69 if (intr->intrinsic == nir_intrinsic_store_deref) {
70 nir_variable *var = nir_intrinsic_get_var(intr, 0);
71 if (var == out) {
72 b.cursor = nir_after_instr(instr);
73 nir_def *load = nir_load_var(&b, in);
74 load = nir_fclamp(&b, nir_channel(&b, load, 0), nir_channel(&b, load, 1), nir_channel(&b, load, 2));
75 nir_store_var(&b, new_out ? new_out : out, load, 0x1);
76 found = true;
77 }
78 }
79 }
80 }
81 }
82 if (!found) {
83 b.cursor = nir_before_impl(impl);
84 nir_def *load = nir_load_var(&b, in);
85 load = nir_fclamp(&b, nir_channel(&b, load, 0), nir_channel(&b, load, 1), nir_channel(&b, load, 2));
86 nir_store_var(&b, new_out, load, 0x1);
87 }
88 }
89
90 nir_metadata_preserve(impl, nir_metadata_block_index |
91 nir_metadata_dominance);
92 return true;
93 }
94
95 bool
nir_lower_point_size_mov(nir_shader * shader,const gl_state_index16 * pointsize_state_tokens)96 nir_lower_point_size_mov(nir_shader *shader,
97 const gl_state_index16 *pointsize_state_tokens)
98 {
99 assert(shader->info.stage != MESA_SHADER_FRAGMENT &&
100 shader->info.stage != MESA_SHADER_COMPUTE);
101
102 nir_variable *out =
103 nir_find_variable_with_location(shader, nir_var_shader_out,
104 VARYING_SLOT_PSIZ);
105
106 return lower_impl(nir_shader_get_entrypoint(shader), pointsize_state_tokens,
107 out);
108 }
109